THPG 174020 / 174021 Porcelain doorbell button

174020: Rocker button with bell symbol for the switch system Porcelain black with solid screw contacts.‎ The central insert is made of black glazed porcelain, the rocker is made of Bakelite and the base body is made of steatite, a proven ceramic material.‎ 174021: Luminescent rocker button with bell symbol for the switch system Porcelain black with solid screw contacts.‎ The central insert is made of black glazed porcelain, the rocker is made of Bakelite with a luminescent insert and the base body is made of steatite, a proven ceramic material.‎ Rocker buttons are particularly suitable for operating bells and door openers, and in conjunction with a relay, they can also be used for stairwell lighting.‎ Rocker buttons with corresponding symbols on the rocker are also available.‎ Further info from manufacturer on 174020 / 174021 THPG